Pressure relief valve for product containers

ABSTRACT

A combined relief valve and lid structure is provided for pre-mix beverage and syrup containers having a tubular body enclosing a relief port in the lid, an annular valve seat surface about the relief port and raised higher than the lid surface and drain ports extending from the valve seat surface down to the lid surface to enhance drainage of the entire internal portion of the valve body. The relief port is closed by a spring biased poppet and has a biasing spring held in place in the top of the tubular body by a one-way detent and retainer clip arrangement which must be destroyed to remove it from the valve body to gain access to the relief valve poppet. The valve cannot be tampered with unless this retainer clip for the valve spring is destroyed. The retainer clip is ported to permit cleaning steam or other fluid to enter the top of the valve and drain off through the drain ports without accumulation of condensate or residual fluid in the valve. The poppet is basically cylindrical with relieved vertical side portions or flats to enhance drainage and exposure of the valve surface for cleaning.

This application is a divisional of copending application Ser. No.739,397, filed on Nov. 18, 1976 and now U.S. Pat. No. 4140148.

FIELD OF THE INVENTION

This invention relates to pressure relief valves and more particularly,to calibrated pressure relief valves for product containers which areformed in or integrated with the lid of such containers.

BACKGROUND OF THE INVENTION

In shipping containers for pre-mixed beverage and syrup products andother liquid products in which it is desirable to maintain sterile andsafe conditions, it is highly desirable to employ pressure relief valvesin the lids of such containers. In fact, it is a voluntary industrystandard of the N.S.D.A. to provide pressure relief valves in soft drinkor other beverage containers which will relieve 30 standard cubicfeet/minute of carbon dioxide at a cracking pressure not to exceed 130psig. This requirement or voluntary standard is to precludeover-pressurization of containers which could result in explosion anddamage.

In designing such relief valves for this purpose, however, there are anumber of criteria which such valves must meet in order to beacceptable. For example, it is highly desirable that such a relief valvebe designed in such a way that it can be washed in commerciallyavailable washing equipment. For example, the top of the valve should beopen to allow jets of hot liquid to enter the valve body and thereforeclean and flush the inner components of the valve.

The housing of the valve, the valve poppet, seat and other componentsshould be constructed such that no liquid can accummulate within thevalve structure and encourage bacterial growth.

The valve should also be tamper proof such that any override of thenormal relief function of the valve will result in the destructionthereof making it obvious that the container has possible beenadulterated or at the least, tampered with.

Finally, the valve should be compatible with the lid structure for suchcontainers such that it can be integrally incorporated in the lidstructure.

It is, therefore, an object of the present invention to provide a newand novel pressure relief valve and lid structure for pre-mixed beverageand syrup containers and the like.

It is another object of the present invention to provide a new and novelpressure relief valve for beverage and syrup containers which is readilyadaptable to sterilization and which will be self draining whensubjected to the action of sterilizing fluids.

Yet another object of the present invention is to provide a new andnovel pressure relief valve for pre-mixed beverage and syrup containerswhich is integrally formed in the lid of such containers and which istamper proof.

These and other objects of the present invention will become more fullyapparent with reference to the following specification and drawingswhich relate to preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a container lid and pressure relief valvestructure of the present invention;

FIG. 2 is a cross section taken along 2--2 of FIG. 1 illustrating oneembodiment of the valve of the present invention in enlarged detail;

FIG. 3 is a top plan view of a valve spring retainer clip of the presentinvention;

FIG. 4 is a cross section taken along line 4--4 of FIG. 3;

FIG. 5 is a top plan view of a preferred embodiment of a valve poppet ofthe present invention;

FIG. 6 is a cross section taken along line 6--6 of FIG. 5;

FIG. 7 is a top plan view of another preferred embodiment of a valvepoppet of the present invention;

FIG. 8 is a cross section taken along line 8--8 of FIG. 7;

FIG. 9 is a top plan view of another preferred embodiment of a valve andcontainer lid structure of the present invention;

FIG. 10 is a detailed cross section taken along line 10--10 of FIG. 9illustrating an integral portion of the valve assembly formed in thecontainer lid;

FIG. 11 is another detailed cross section illustrating the valve seat ofFIGS. 9 and 10 taken along line 11--11 of FIG. 9; and

FIG. 12 is a perspective of a resilient sealing disk of the presentinvention.

SUMMARY OF THE INVENTION

The relief valve of the present invention cooperates with a containerlid having a valve port defined through the surface thereof with araised annular curb around the port defining a valve seat surfaceprojecting above an intermediate annular surface which is raisedslightly above the remainder of the surface of the lid.

In another embodiment of the invention, the port in the container lid isof a size to receive an integral valve body and valve seat having thevalve port in the valve body structure but with the raised annular curband valve seat surface and intermediate surface maintained above theremainder of the surface of the lid surrounding the valve port therein.

A nylon or other preferrably non-metalic valve poppet carries aresilient sealing disk in a truncated cylindrical cavity overlying theraised annular curb of the valve relief port is spring biased to engagethe sealing disk with the valve seat on the raised annular curb by acalibrated compression spring. This compression spring is maintained inplace above the valve poppet in a stainless steel tubular valve body bymeans of a frangible snap-in retainer means which must be broken inorder to remove the relief valve from the container. This retainer meansis insertable into the upper end of the tubular valve body, the latterincluding a plurality of internal grooves and recesses which are of aone-way nature and which cooperate with a plurality of spring fingers ordetents integral with the retainer means to permit one-way access of theretainer means and lock the same in place in the valve body such thatonly breakage of the retainer means will permit its removal.

The tubular valve body is provided with drain ports having theirlowermost extremities positioned beneath the level of the annular valveseat and its surrounding intermediate surface and extending radiallyoutward therefrom to permit cleaning fluid or condensation to draincompletely away from the valve seat surface and intermediate surface andpreclude the formation of bacteria adjacent the seat and intermediatesurface elsewhere and within the valve body.

Cleaning is further facilitated by the fact that co-axial with thecentral line of the compression spring, the spring retaining clip isported and relieved with a central axial bore such that hot cleaningfluid or steam may be injected into the valve assembly through thespring retaining means and thoroughly sterilize all of the components ofthe relief valve which are exterior to the container lid into which therelief valve is integrated.

In one preferred embodiment of the invention, the tubular valve body ismerely rested upon two arcuate upset portions in the container lid andthe raised annular curb and its integral valve seat surface areintegrally formed in the container lid such that no special machiningother than the one-way grooves and recesses for holding the retainingmeans for the compression spring need be machined or formed into thevalve body.

The valve poppets may either be basically cylindrical, triangular orrectangular in overall shape and have a truncated cylindrical cavitytherein containing a resilient sealing disk which engages the valve seatsurface on the raised annular curb to seal the valve port.

The valve poppet includes an annular shoulder depending beneath thesealing disc to engage the intermediate surface adjacent the valve seatupon sufficient compression of said sealing disk.

The sealing disk and lower annular shoulder of the valve poppetcooperate, respectively, with the annular valve seat (and its raisedcurb) and the intermediate surrounding surface to apportion the counterforces required to oppose the force of the valve spring. The forceexerted by the spring is taken up partially by the compression of theresilient sealing disc against the valve seat and curb and the remainderby the lower annular shoulder of the poppet engaging the surroundingintermediate surface or web in the lower portion of the valve body. Theratio of the two counter forces is controlled such that the load assumedby the sealing disk is just sufficient to maintain an effective seal atpressures just below and up to the desired cracking pressure. Thisprecludes sticking and resultingly higher cracking pressures thandesired. Thus, the accuracy and reliability of the relief valve isenhanced.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1 of the drawings, a relief valve 20 of the presentinvention is shown as mounted integrally with a lid 22, the latterhaving a container rim engaging bead or peripheral curl 24 and a centralweb or container covering portion 26 in which the relief valve 20 ismounted.

With further specific reference to FIGS. 2, 3 and 4, the relief valve 20is shown as comprising a stainless steel tubular valve body 20A havingthe outer end thereof internally relieved in the provision of one-wayretaining grooves 20B and a one-way retaining recess 20C at theinnermost extremity of the retaining grooves 20B for receiving a nylonspring retaining clip 20D which, as shown in FIG. 3, has a basicallycruciform top plan configuration. This configuration includes outboardarcuate detents 20D1-20D4 alternately dispersed about the periphery ofthe retaining clip 20D with radially relieved gaps 20D5-20D8. The springretaining clip 20D is further provided with an axial and centrallylocated enlarged bore 20D9 which is sized to receive cleaning liquid orsteam into the valve body 20A as will be hereinafter more fullydescribed.

The spring retaining clip 20D is made of molded nylon or the like andits cruciform shape enables it to be forced into the uppermost end ofthe valve body 20A past the one-way retaining grooves 20B by distortionof the annular segmental detents 20D1-20D4 to ultimately permit thelatter to snap into the retaining recess 20C which is conformally shapedto receive them.

In this regard, the upper or reverse direction corners of the recess 20Care substantially right angular in configuration as are the top detentsurfaces of the detents 20D1-20D4.

Also, to permit more facile entry of the spring retainer clip into thetop of the stainless steel body 20A, the lowermost outer extremities ofthe arcuate detents 20D1-20D4 are bevelled and a similar bevelled edgedis provided on the innermost extremity of the conformal retaining groove20C.

The lowermost portion of the spring retainer clip 20D is counterboredco-axially with the axial bore 20D9 as generally indicated by the dottedlines in FIG. 3 and in cross section in FIG. 4 in the provision of anannular spring keeper surface SK1 surrounding the axial bore 20D9 andalso providing, by way of the counterbore an interrupted arcuateperipheral shoulder SK2 which is sized to receive a snug or juxtaposedengagement one end of the valve spring VS.

The container cover or central web portion 26 of the lid 22 is drilledor otherwise relieved to form a valve receiving port 28 into which astepped-down end 20E of the stainless steel tubular valve body 20A ispress-fitted or welded.

The stepped down end 20E of the cylindrical valve body 20A is providedwith a web or flange which extends across the valve body parallel to thelid surface 26 but which at its inboard extremity is raised above thelid surface 26 in a provision of an annular intermediate web surface 20Fsurrounding a raised annular curb 20G. The valve seat surface 20GA is anannular surface defined by the upper extremity of the raised annularcurb 20G which defines the perimeter of a relief bore 20H defined in theintermediate web.

A drain port or plurality of drain ports 20J extends radially throughthe wall of the valve body 20A immediately adjacent the annularintermediate web 20F with the lowermost extremity of the drain ports 20Jpositioned below the web 20F and the valve seat 20GA as indicated at20J1 in FIG. 2.

The shape of the drain ports 20J is such that there are no upstandingliquid retaining edges at the vicinity of the demarcation point 20J1between the lowermost extremity of the said ports and the intermediateweb 20F.

To complete the valve assembly, a valve poppet 20K having a truncatedcylindrical bore 20K1 therein, which is concentrically and externallydisposed with respect to the upstanding annular curb 20G surrounding therelief valve port 20H, and which carries a resilient sealing disk 20K2which compressibly and resiliently engages the valve seat 20GA on thecurb 20G to seal off the port 20H. An annular flat bottom shoulderportion 20K3 of the valve poppet 20K surrounding and depending beneaththe sealing disc 20K2 mates wih the intermediate web 20F uponcompression of the sealing disc 20K2 under the force of the valve springVS.

On the uppermost end of the valve poppet 20K is provided an annularshoulder SK3 which is horizontally disposed and which is a spring keepersurface for the lowermost end of the valve spring VS. An upstandingreduced diameter portion SK4 is also provided in the valve poppet 20Kwhich extends above the annular shoulder SK3 internally of the valvespring VS and serves as a lateral keeper for the lowermost end of thesaid valve spring VS.

Referring jointly to FIGS. 2, 5, 6 and 12, the valve poppet 20K is shownin a first preferred embodiment as being basically triangular in topplan view and having arcuate apices 20K4 interconnected by flat sidewall surfaces 20K5 which are disposed along cords of the circle definingthe outer periphery of the apices 20K4, the latter being all symmetricalone with the other.

Thus, there is provided a valve poppet configuration around whichcleaning liquid or steam can readily flow and around which drying air orthe like can readily circulate such that no fluid will be trapped withinthe bore of the valve body 20A by the poppet 20K, the latter beingdimensioned such that it does not engage the interior bore of the valvebody 20A but rides relatively freely therein against the action of thevalve spring VS.

With reference to FIGS. 7 and 8, an alternate form of the valve poppet20KA is illustrated which includes the annular keeper SK3A and thelateral keeper and extension SK4A (all like components to the valvepoppet 20K being identified by like designations with the suffix A), thetruncated cylindrical bore 20K1A, the resilient sealing disk 20K2A andthe intermediate web engaging lower annular surface 20K3A. In top plan,however, the valve poppet 20KA is basically square with four rounded orarcuate outboard corners 20K6 interconnected by flat vertical surfaces20K7 lying along cords of the arc or circle defining the peripheries ofthe outboard corners 20K6. Here again, as in the embodiment of FIGS. 5and 6, the poppet 20KA at its maximum dimension (across thediametrically opposed outboard corners 20K6) is less than the internaldiameter of the valve body 20A such that the valve poppet 20KA will ridewithin the valve body 20A relatively freely against the action of thevalve spring VS.

The end result of the basically square shape of the valve poppet 20KA isthe same as that with the basically triangular shape, namely, that therelieved side portions 20K7 provide room for both the cleaning liquid orsteam and drying air to circulate around the valve poppet within theconfines of the valve body 20A to thereby preclude any collection ofliquid and resulting bacterial growth within the valve body 20A.

Referring now to FIGS. 9, 10 and 11, another preferred embodiment of therelief valve of the present invention will now be described with respectto the configuration of the valve body 20A and the container lid 22 inwhich it is mounted. The valve poppet assemblies 20K, 20KA, the valvespring VS and the valve spring retainer clip 20D are all identical tothose already described with reference to FIGS. 1-8 and 12 and will notbe shown in connection with FIGS. 9, 10 and 11 for the sake ofsimplicity.

In this embodiment, the fabrication of the valve body is simplified inthat instead of a closed end, stepped-down, cylindrical tube, thecylindrical tube comprising the valve body of the embodiment of FIGS. 9,10 and 11 is open at both ends and the valve seat and drain ports areintegrally formed in the lid of the container.

Specially, reference is now made to FIG. 9, 10 and 11 in which partshaving like functions (albeit different structures) from those of FIGS.1-8 will be identified by like numerals with the prefix one hundred(100).

The relief valve body 120A of the relief valve assembly 120, the latterbeing shown without the retainer spring and poppet thereof, is shown asincluding the one-way retainer slots 120B and the inboard retainerrecess 120C as previously described with respect to the elements 20B and20C in FIG. 2. The basic cross sectional configurations of the retainerslot 120B and the conformal retaining recess 120C are clearly shown inFIG. 10.

The lower portion of the valve body 120A terminates in a right angularcut defining a sharp bottom edge 120A1 on the valve body 120A and the120A1 is welded to first and second arcuate convex dimples 122A and 122Bwhich are disposed in symmetrical opposition about the center of arelief valve bore 120H. This bore 120H is formed with the annular raisedcurb 120G in the surface 126 of the container lid 122 which has beenupset to provide the upstanding annular curb 120G and annular valve seatsurface 120GA and its adjacent annular intermediate web 120F which isdefined at its outer extent by the arcuate convex dimples 122A and 122Bwhich are upset portions of that same surface 126 of the lid 122.

As previously taught with regard to the embodiment of FIGS. 1 and 2,there are provided a pair of drain ports which extend radially beneaththe right angle bottom surface 120A1 of the valve body 120A between theends of the convex upset dimples 122A and 122B so as to provide firstand second drain openings 120JA and 120JB which are radially disposedalong a common diameter. Further, as previously described, the lowermostextent of these drain ports 120JA and 120JB (the top to the lid surface126) is beneath the annular valve seat 120GA and the intermediate web120F at respective junctures 120J1A and 120J1B such that any liquid onthe said valve seat and the web will flow outwardly through the drainports and will not accumulate within the confines of the valve body120A, thereby precluding the formation of bacteria within the valvebody.

The resilient sealing discs 20K2, 20K2A and the lower annular shoulders20K3, 20K3A of the valve poppets 20K, 20KA, respectively, each take uprespective portions of the load exerted on the said valve poppets by thevalve spring VS.

The compression of the resilient sealing disks 20K2, 20K2A against theraised annular valve seats 20GA, 120GA on the annular curbs 20G, 120Gtakes up a portion of the force exerted on the poppets 20K, 20KA by thevalve spring VS. The remainder of this spring force is opposed by theengagement of the lower annular shoulders 20K3, 20K3A with the annularintermediate webs 20F, 120F.

The ratio of the amount of counter forces exerted by the sealing disks20K2, 20K2A and the poppet shoulders 20K3, 20K3A and their respectiveabutments with the valve seats 20GA, 120GA and intermediate webs 20F,120F is quite important for maximum reliability of the valve structure.

If, for example, too much of the load of the valve spring VS is assumedby the sealing disks 20K2, 20K2A then they tend to stick on the valveseats 20GA, 120GA and create higher cracking pressures than desired.

It has been established experimentally that the characteristics thevalve spring VS and sealing disks 20K2, 20K2A should be chosen such thatthe sealing disks are compressed just enough to effectively seal thevent port 20H, 120H over the desired range of operating pressures.

The thickness and compressibility of the sealing disks 20K2, 20K2A thusdetermine how much counter force is generated against the raised curb20G and the valve seat 20GA by the compression of the said disks beforethe annular shoulders 20K3, 20K3A engage the intermediate web 20F togenerate the necessary remaining counter force to the valve spring VS.Thus, the initial, unstressed displacement between the sealing disks20K2, 20K2A and the annular shoulders 20K3, 20K3A of the valve poppets20K, 20KA are another design parameter for establishing the proper ratioof counter forces in the poppet assembly for opposing the valve springVS.

For example, in a compressible material suitable for sealing a valveseat such as 20GA for cracking pressures on the order of 100 psi to 130psi, the raised curb 20G should compress the disk 20K2 on the order of0.020 inches over the area of contact with the valve seat 20GA.

The free board or freedom of movement afforded the valve poppets 20K,20KA within the interior of the valve body 20A, 120A is provided byhaving the inside diameter of the said valve bodies and the maximumdiameter of the valve poppets differ, for example, on the order of 0.01inches. Thus, the fit is relatively close to properly guide the poppetup and down against the action of the spring VS while at the same timeproviding sufficient freedom of movement to permit for thermal expansionand contraction depending upon environmental conditions. Further, whilethe preferred valve poppet shapes are triangular and rectangular asshown, poppets with cylindrical or other shapes are also contemplated.

Likewise, the spring fingers or arcuate detents 20D1-20D4 on the springretainer clip 20D permit expansion and contraction of the molded nylonretainer 20D within the bore of the valve body 20A and the force fit ofthe spring fingers into the retaining groove 20C and the additionalaction of the one-way grooves 20B tend to preclude undue movement orbacking out of the retainer clip 20D from the valve body 20A, 120A. Thisadvantage is in addition to the fact that in order for the valve poppetto be reached to override the action of the relief valve in its normalautomatic mode of operation, one must destroy the retainer clip 20D inorder to gain access to the interior of the valve body 20A, 120A.

In operation, referring primarily to FIG. 2 which typifies therelationship between the valve poppet 20K, the relief port 20H, thevalve spring VS and the retainer clip 20D, and the relative position ofthe valve seat 20GA, intermediate web 20F and the drain ports 20J,excess pressure within the container lid acting through the valve port20H against the resilient sealing disk 20K2 within the confines of thecurb 20G and valve seat 20GA will overcome the action of the spring VSand lift the valve poppet 20K and sealing disk 20K2 off the valve seat20GA and also lift the annular shoulders 20K2A off of the intermediateweb 20F. Therefore, pressurized contents beneath the surface 26 of thecontainer lid will be ejected around the valve poppet 20K over the seat20GA and intermediate web 20F and out through the drain ports 20J. Ifthe flow is sufficiently severe, it can also exhaust through the centralbore 20D9 and the relieved portions 20D5-20D8 of the spring retainerclip 20D.

After such an emission of unduly pressurized contents, if it is desiredto re-use the container lid or to clean the container lid and reliefvalve assembly in the first instance, then steam or hot cleaning liquidmay be emitted directly downward into the valve body 20A through thecentral bore 20D9 of the spring retainer clip 20D and completelysterilize the interior of the valve body 20A including the externalsurfaces of the poppet 20K, the spring VS and the exposed portions ofthe intermediate web 20F. Then, upon removal of the injection equipmentfor the cleaning fluid or steam, the remaining fluid or condensatewithin the valve body 20A can flow outwardly from the intermediate web20F through the drain ports 20J because of the difference in height atthe demarcation point 20J1 of the drain port 20J and the intermediateweb 20F. Therefore, no fluid will remain within the valve body and thesterilization will be complete. The absence of any remaining or residualfluid within the valve body 20A will preclude the growth of bacteriatherein.

As can be readily seen from the foregoing specification and drawings,the present invention provides a new and novel vent valve for pre-mixedbeverage and syrup containers which satisfies a need in the art for avalve that is tamper proof, readily cleanable and sanitary, is low incost, easy to assemble and readily controllable to provide desiredcracking pressure and relief capacities.

It should be understood that the apparatus of the present invention maybe modified as would occur to one of ordinary skill in the art withoutdeparting from the spirit and scope of the present invention.

I claim:
 1. Sanitary pressure relief valve and lid means for liquidproduct containers comprising:a central web in said lid having a raisedannular valve seat surface formed therein and a relief port through saidvalve seat surface and said web, said web further comprising an annularintermediate web surface surrounding said raised seat surface; at leasta pair of spaced arcuate bosses integrally formed in said lid and raisedabove said annular valve seat surface and said intermediate web surfaceand partially enclosing said intermediate web surface; a tubular valvebody having one end open and its other end integrally affixed to saidarcuate bosses and defining, with said bosses, drain ports forcommunicating the annular web surface with the exterior of said valvebody; valve poppet means selectively closing said relief port seated onsaid annular valve seat; valve spring means in said valve body engagedwith said poppet; spring retainer means inserted in said one open end ofsaid tubular valve body maintaining said valve spring means inengagement with said valve poppet means; said spring retainer meansincluding access ports formed therein for admitting cleaning fluids tothe interior of said valve body to sterilize said relief valve assembly;and said drain ports acting to drain said cleaning fluids andcondensates thereof from said relief valve assembly.
 2. The inventiondefined in claim 1, wherein said valve poppet is basically cylindricalwith flattened axially extending side surfaces about its peripheryadjacent said drain ports and said valve seat to enhance drainage andpreclude entrapment of fluids and condensates between said poppet andsaid valve body.
 3. The invention defined in claim 1, wherein saidspring retainer means comprises a one-way interlocking resilient cliphaving locking detent means extending into said valve body; andwhereinsaid valve body includes integral internal locking means conformallyshaped to receive said detent means to preclude intact removal of saidclip from said valve body.
 4. The invention defined in claim 1, whereinsaid valve poppet means comprises a poppet body having a downwardlydirected cylindrical recess defined therein, a resilient compressibledisk means carried in said cylindrical recess for engaging said valveseat and an annular shoulder surrounding said disk means and saidrecess; andwherein said resilient disk means is seated on said raisedannular valve seat and said annular shoulder is seated on saidintermediate web surface surrounding said raised annular valve seat inthe closed condition of said relief port.
 5. The invention defined inclaim 4, wherein said resilient disk means is compressed on said annularvalve seat by said valve spring to generate a first counter forceopposing said valve spring and said annular shoulder engages saidintermediate web surface to generate a second counter force sufficientto fully oppose the force of said valve spring.
 6. The invention definedin claim 5, wherein said resilient disk means is recessed within saidannular shoulder; andwherein said annular valve seat includes raisedcurb means for maintaining said valve seat above said intermediate websurface and within said annular shoulder in the closed condition of saidrelief port.